X-ray generating device and x-ray-generating-device control

Abstract

An X-ray generating device ( 10 ) is provided with an electron gun ( 12 ) that generates an electron beam, a linear accelerator ( 14 ) that accelerates, by means of microwaves, the electron beam generated by the electron gun ( 12 ), an X-ray target ( 16 ) that generates X-rays by being irradiated with the electron beam accelerated by the linear accelerator ( 14 ), a microwave generating device that generates microwaves to be introduced into the linear accelerator ( 14 ), and a pulse modulator that controls the microwave generating device so as to change the power of the microwaves. Because the linear accelerator ( 14 ) includes a plurality of buncher cavities ( 40 ), even if there are electrons that are shifted out of the acceleration phase when the power of the microwaves is decreased, these electrons can be accelerated in the acceleration phase of the next time period; therefore, a decrease in the intensity of an electron beam to be emitted is suppressed even if the power of the microwaves is decreased.

1 . An X-ray generating device comprising:
 an electron-beam generating unit for generating an electron beam;   a linear accelerator that includes a plurality of buncher cavities and a plurality of accelerating cavities and that accelerates, by means of microwaves, the electron beam generated by the electron-beam generating unit;   a target that generates X-rays by being irradiated with the electron beam accelerated by the linear accelerator;   a microwave generating unit for generating microwaves to be introduced into the linear accelerator; and   a controlling unit for controlling the microwave generating unit so as to change the power of the microwaves.   
     
     
         2 . The X-ray generating device according to  claim 1 , wherein the controlling unit changes a frequency at which the microwaves are repeatedly introduced in a pulsed manner in accordance with the magnitude of the power of the microwaves to be introduced into the linear accelerator from the microwave generating unit. 
     
     
         3 . The X-ray generating device according to  claim 1 , wherein the controlling unit generates high-energy X-rays by introducing the microwaves having a power corresponding to that during the rated operation into the linear accelerator from the microwave generating unit, and generates low-energy X-rays by introducing the microwaves having a power lower than the power of microwaves during the rated operation into the linear accelerator from the microwave generating unit. 
     
     
         4 . An X-ray generating device comprising:
 an electron-beam generating unit for generating an electron beam;   a linear accelerator that accelerates, by means of microwaves, the electron beam generated by the electron-beam generating unit;   a target that generates X-rays by being irradiated with the electron beam accelerated by the linear accelerator;   a microwave generating unit for generating microwaves to be introduced into the linear accelerator; and   a controlling unit for controlling the microwave generating unit so as to change the power of the microwaves,   wherein the controlling unit changes a frequency at which the microwaves are repeatedly introduced in a pulsed manner in accordance with the magnitude of the power of the microwaves to be introduced into the linear accelerator from the microwave generating unit.   
     
     
         5 . A control method of an X-ray generating device provided with an electron-beam generating unit for generating an electron beam; a linear accelerator that includes a plurality of buncher cavities and a plurality of accelerating cavities and that accelerates, by means of microwaves, the electron beam generated by the electron-beam generating unit; a target that generates X-rays by being irradiated with the electron beam accelerated by the linear accelerator; a microwave generating unit for generating microwaves to be introduced into the linear accelerator; and a controlling unit for controlling the microwave generating unit so as to change the power of the microwaves, the control method comprising:
 introducing microwaves having a power of a first magnitude into the linear accelerator from the microwave generating unit, of accelerating the electron beam generated by the electron-beam generating unit, and of generating X-rays by radiating the electron beam onto the target; and   introducing microwaves having a power of a different magnitude from the microwave power of the first magnitude into the linear accelerator from the microwave generating unit, of accelerating the electron beam generated by the electron-beam generating unit, and of generating X-rays by radiating the electron beam onto the target.